There is no documented success rate, and you don't have to believe in god. You have to believe in a higher power, or anything that you can look forward to. For me, I don't believe in god, but my higher power is doing the next best thing. I believe if you mainly focus on doing good things, I prevent bad things from happening. Like I said, every attic will never be cured, but like any other disease, there are ways to avoid side affects.